GB851345A - Hydraulic core drill - Google Patents

Abstract

851,345. Drilling rock. WALLACE, J. G. June 10, 1959 [June 23, 1958], No. 19832/59. Class 85. A rock drill assembly comprises a frame having side rods 5 which are connected by cross-members 6, 7, 8 and serve as guides for the drill-driving means, the rods 5 being pivotally connected to rock bolts 59 in the rock-face and supported at the required inclination by telescopic legs 60. The hydraulic motor 18 and bearing 17 are secured to a base plate 23 which is detachably secured on a plate 13 joining cross-members 14 having bearings 15 sliding on the rods 5. The member 6 also carries a bearing 37 for the drill string which is supplied with water by a pump 21 connected to a swivel 19. The feed of the drill is effected by a double-acting hydraulic cylinder 38, and the motor 18 and cylinder 38 are controlled by by-pass valves 31, 53. If a rock-face is not available for the rock-bolts 59, a timber or concrete bed may be laid for the attachment. When the drill string is to be pulled out of the bore, the plate 23 with the motor 18 and bearing 17 are removed from the plate 13, and a clamp device comprising a U- shaped strap 66 which embraces the drill rod 35 and has, pivoted at 69 between its legs a camended lever 78 which protrudes through a slot 71 in the plate 13 and is pinned loosely therein by a pin 72. When the cylinder 38 is operated to move the carriage 13, 14 away from the rock-face, the cam 70 is moved to grip the drill rod 35 and pull it out of the bore. When the cylinder 38 is reversed, the cam 70 is swung into inoperative position and the strap 66 slides feely on the rod 35.